Charles met Palestinian Muslim clerics outside Bethlehem's Omar Ben al-Khattab mosque in 2020
Charles met Palestinian Muslim clerics outside Bethlehem's Omar Ben al-Khattab mosque in 2020 AFP

In a hushed atmosphere of a south London mosque, a dozen Muslims of all ages wait to sign a book of condolences for Queen Elizabeth II at an interfaith ceremony.

In contrast to when she acceded to the throne in 1952, she died last week with Britain now multi-cultural and multi-faith, as well as increasingly secular.

That decades-spanning transition appears to have left the country's growing Muslim population with a strong appreciation for the UK's longest-serving monarch.

"I'm a first generation Muslim in this country," said Danial Saeed, a reserved 19-year-old wearing foggy glasses and a face mask.

"We got to practise our faith in this country under the protection of our queen."

The UK's head of state remains a figurehead for the Anglican community, holding the centuries-old title "Defender of the Faith and Supreme Governor of the Church of England".

At Charles's future formal coronation, Archbishop of Canterbury Justin Welby will anoint him with holy oil and bless the new king.

Although the monarchy is deeply anchored in Christianity, Charles has previously insisted that when he takes the throne he will feel a responsibility to defend all faiths.

In his inaugural address last week, he noted that British society had "become one of many cultures and many faiths" during his mother's record-breaking 70-year reign.

But in a sign of the delicate balancing act required in his new role, he also heralded "the sovereign's particular relationship and responsibility towards the Church of England".

He also added his own Anglican faith was "deeply rooted".

In the huge Baitul Futuh mosque in south London, Rafiq Hayat, head of the Ahmadiyya Muslim Community organisation, predicted a seamless transition in relations with Charles III.

"Our loyalty to the king will be just as strong as it was to her majesty the queen," he told AFP.

Hayat argued Charles has "a great relationship with the Muslim world", noting he had praised the teachings of Islam and recited Koranic verses in the past.

"I think he feels that Islam is very much sitting comfortably with Christianity and other world faiths," he said.

On Friday, the new monarch will receive representatives of the main religions practised in Britain at Buckingham Palace, in another sign of his intent to reach out beyond the Christian faith groups.

The king brought forward the audience in order to allow Chief Rabbi Ephraim Mirvis to be able to return home in time for the Jewish Sabbath, which starts Friday at 17:59GMT.

A source close to the Chief Rabbi told BBC News the decision to bring the event forward was an "amazing gesture of respect and thoughtfulness".

Ian Bradley, theology professor at the University of St Andrews, said the British monarch's role is "to bind the nation together in all sorts of ways but not the least in terms of faith".

And that does not need to be restricted to Christianity, he said, noting some of the strongest supporters of monarchy belong to minority faiths in Britain.

Rami Ranger, president of the British Sikh Association, said the late queen gave his community "an immense sense of security".

"She was above party politics and could unite the nation regardless of race, religion and colour," he added.

Bradley believes there is a wider "spiritual dimension" to the UK monarchy which provides a "spiritual heart" to the country's so-called unwritten constitution, that has evolved over centuries.

"It's very different from France... being a very clearly secular state and having a secular constitution," he added.

"We are now largely a post-Christian secular nation, but a lot of people still like that the monarchy still has that religious aura."

Echoing Hayat, Bradley points out that while Charles is a church-going Christian, he is "very interested in Islam (and) in spirituality in general".

Just as the new king's well-known stances on environmental issues resonate in particular with young people, his openness regarding religion could chime with his subjects in Britain and beyond.

Among Christians, he has shown a particular fondness for the Orthodox faith, making several retreats to monasteries on Mount Athos in Greece.

Meanwhile he also touched Britain's Jewish community by visiting Israel -- something his late mother never did -- though it was not on an official visit.

Charles also commissioned portraits of Holocaust survivors, a gesture of remembrance that was also appreciated.

For Hayat, the new king is well placed when it comes to talking about faith.

"When he speaks people listen," he said.

"That will be a very important message that he will send out to the whole world that Islam is a religion of peace and that Islam is not associated with terrorism.

"That will make a huge difference to the relationship between the Muslim world and the Christian world and the Jewish world."

In India in 2013, Charles met Swami Chidanand Saraswatiji, president and spiritual head of the Parmarth Niketam Ashram, during the Sunset "Aarti" ceremony by the River Ganges, which is sacred to Hindus
In India in 2013, Charles met Swami Chidanand Saraswatiji, president and spiritual head of the Parmarth Niketam Ashram, during the Sunset "Aarti" ceremony by the River Ganges, which is sacred to Hindus AFP
Charles distributed Maundy money during the Royal Maundy Service at St George's Chapel in Windsor, west of London, in April
Charles distributed Maundy money during the Royal Maundy Service at St George's Chapel in Windsor, west of London, in April AFP
The British Sikh Association said the late queen Elizabeth II was a uniting figure
The British Sikh Association said the late queen Elizabeth II was a uniting figure AFP